Apparatus for operating molded fiber drying dies



jan. 13, 1953 CHAPUN 2,624,956

APPARATUS FOR OPERATING MOLDED FIBER DRYING DIES 3 Sheets-Sheet 1 Filed Nov. 8, 1946 INVENTOR;

Jan. 13, 1953 M. P. CHAPLIN 2,624,956

APPARATUS FOR OPERATING MOLDED FIBER DRYING DIES Filed Nov. 8, 1946 3 Sheets-Sheet 2 INVEHTOR- Jan. 13, 1953 M. P. CHAPLIN APPARATUS FOR OPERATING MOLDED FIBER DRYING DIES 3 Sheets-Sheet 3 Filed Nov. 8. 1946 INVEHTOR- Patented Jan. 13, 1953 OFFICE APPARATUS FOR OPERATING MOLDED FIBER DRYING DIES Merle P. Chaplin, Portland, Maine Application November 8, 1946, Serial No. 708,661

This invention is an improvement upon machines of the general character disclosed in my Patent No. 2,388,828, issued November'13,'1945. In that machine, pulp is suction-formed froma liquid-pulp mixture on forming 'dies supported on a carrier, mounted to rotate about a horizontal axis above the pulp tank. As the carrier rotates, the forming dies pass through the pulp tank and wet pulp is accreted thereon. Through continued rotation of the carrier, the pulp ar- 6 Claims. (Cl. 34-146) ticles thus deposited are moved into a horizontal v position above the tank and are successively removed from the forming dies by transfer dies which transfer these articles to a drying unit in which the articles are finished.

This drying unit comprises a plurality of pairs of mating drying dies. The dies of each mating pair are alined on a vertical axis, with the upper drying die stationary and the lower drying die movable toward and away from the same, so that wet articles positioned between the drying dies, when in opened position, may be compressed and dried by said dies when they are brought together upon the interposed article. The several pairs of drying dies are arranged in angular sequence for rotation through a cir cular path about the fixed vertical axis of such path and they are bodily rotated intermittently through step by step increments to receive articles in succession from the transfer dies.

Vertical reciprocation of the lower drying dies, to move them toward and away from the relatively stationary upper drying dies is accomplished, in the machine of said patent, by a stationary arcuate cam track, concentric with and positioned beneath the spindles which carry these lower drying dies and these spindles have, at their lower ends, cam followers in the form of rollers adapted to traverse the track as the drying unit rotates. The arcuate cam is so configurated that it permits lowering i the lower drying dies into the feeding position, i. e., in theposition wherein the wet fibre articles are fed to these dies in succession and, as the unit rotates step by step, these cam follower rollers engage with an ascending or lifting phase of the cam track which is sufficiently abrupt to cause a relatively quick closing of the drying dies. As the drying unit rotates, the pulp articles are compressed and dried between the drying dies which are forced together by the cam track until the drying is completed, whereupon the cam track is configurated to abruptly lower the lower drying dies in succession to permit the removal of the thus compressed and dried pulp articles.

The machine of said prior patent performs its functions satisfactorily but considerable power is required to abruptly raise the lower drying dies into closed position and it is desirable for this'and other reasons to more eflicientl operate these lower drying. dies. The present invention provides means whereby this isaccomplished'. v v.

'According to this inventionQa cam track-is utilized to maintain the drying dies in compressing and drying relation with the pulp article during the greater portion of the rotary cycle of the drying unit and to control the pressure applied to said articles during this period. However, the utilization of the cam track to preliminarily close these drying dies by an abrupt rise in the track and to subsequently lower them by an abrupt drop in such track is entirely eliminated. In contradistinction, the cam track is substantially horizontal throughout and the preliminary closing and subsequent opening of the drying dies are accomplished by means of vertical reciprocating plungers functioning after the manner of elevators. The rotary movement of the drying unit servesto successively bring the cam followers of the lower drying dies, while in lowered positions, to a point slightly in ad; vance of and below the forward end of the'hori; zontal'track, where one of said elevators, which may be referred to as the lifting elevator, operates to raise them in succession to the level of the cam track and thus close these die couples. The followers traverse the track and, as they successively arrive at the rear end thereof, they pass onto another elevator, referred to as the lowering elevator, which lowers them to open the drying dies. During the periods during which the lowered dies move from cooperative relation with the lowering elevator to the lifting elevator, the drying die couples remain open and the finished dried articles are first removed and fresh molded articles are thereafter applied. to

the dies before they reach the lifting elevator, In the preferred form of the invention, .the two elevators are operable from a common source of power and are interconnected, ,so that the weight imposed by a die on the lowering elevator will serve to substantially counterbalance the weight of another die on the lifting elevator. Thus, very little power is required to operate these elevators and shocks and jars, such as are apt to be produced by abruptly ascending and descending cam phases are entirely avoided.

In addition to the utilization of elevators in combination with a substantially flat cam track, as stated, the present invention provides for very nice adjustment of such cam track to insure the most desirable pressures upon the pulp articles during the entire drying cycle, with such variations in pressure during different portions of the cycle as may be conducive to the best results, all as more clearly set forth in the followin detailed description.

Features of the invention, other than those adverted to, will be apparent from the hereinafter detailed description and appended claims, when read in conjunction with the accompanying drawings.

The accompanying drawings illustrate one practical embodiment of the invention, but the construction therein shown is to be understood as illustrative, only, and not as defining the limits of the invention.

Figure 1 shows portions of a drying unit, like that of said patent, in vertical section taken substantially in the plane of the line I-I of Figure 2, but showing the drying dies and their spindles in elevation and also showing the elevators and the means for operating the same, in elevation.

Figure z is a plan view of the elevator operating mechanism, showing the elevators and cam tracks in plan and with the positions of the lower drying dies indicated in phantom. In this view many parts of the drying unit are omitted in the interest of clearness.

Figure 3 is a side elevation looking from the lower side of Figure 2 and illustrating the lowering elevator and an adjacent section of the cam track and the means for yieldably supporting the latter.

Figure 4 is a similar view but illustrating the lifting elevator.

Figure 5 is a section on the line 5-5 of Figure 3.

To simplify detailed description of this apparatus, I have used in the accompanying drawings, where practical to doso, reference numerals corresponding to those used for like parts in the patent hereinbefore referred to. For example, in Figure 1, 'I designates a hollow vertical shaft mounted in a pedestal HlI supported on the base 20. Suitable radial and thrust bearings permit easy rotati-ve movement of the shaft. The upper portion of the shaft carries a plurality of radial arms I02 on which are mounted brackets I03. The upper drying dies 80 are secured to heater plates M which are supported through spacers 83 and bolts 82 on the brackets I03. drying dies 90 are mounted on heater plates 9| which are supported on spacers secured to the upper ends of spindles I05. These spindles are adapted for vertical reciprocation through bearings 102a carried by the arms I02, and the corresponding upper and lower drying dies and their spindles are arranged in vertical coaxial alinement. 'To the arms I02 is affixed an annular.

gear 80, driven by a bevel gear 28, which serves to rotate the drying unit about "the axis of the shaft I 0I and, as explained in the patent, this rotation is intermittent with intervening periods of 1651301 :dwell.

The lower ends of each spindle I carries a head IE6 and at the opposite sides of this head are dual cam followers in the form of rolls I01. The cam track I108 with which these followers cooperate extends about the unit through somewhat more than one-half of the circumference of the base 20. It is supported on the base in a :manner hereinafter .more fully explained, so "as to occupy a generally horizontal position and is shown in the drawings as comprising a pair of spaced apart run-ways which the anti-friction rolls I01 of the several lower drying die spindles traverse. As indicated by the arrow .in Figure 2, the drying dies rotate about the axis of the unit in a counterclockwise direction so that, in traversing this track, the cam followers I01 first engage the track at its forward end, indicated at R The lower in Figures 2 and 4 and they leave the track at its rear end, indicated at L in Figures 2 and 3. While these cam followers are traversing the track, the lower drying dies will be in raised positions to close the die couples upon the pulp article to be dried. While the spindle rollers are traveling from the rear end of the track to the forward end thereof, they will be disengaged from the track and the lower drying dies will be in lowered position, so that th drying die couples will be opened to permit of the removal of a finished article therefrom or the placement of a newly formed article between them.

These two distinct positions (i. e. raised and lowered positions) of the lower drying die .followers It? will be clear from Figures .3 and 4, whereinthey are shown in their upper positions at the horizontal level of the track I86 and in their lower positions between the points L and R. The raising of the followers from their lowered positions to the raised positions at the forward or R end of the track and the subsequent lowering of them from the rear or L end of the track is accomplished by the elevators of this invention, next described in detail.

Adjacent the forward and rear ends of the track I08 are upright plungers 30! and 302, respectively, guided for vertical reciprocation in appropriate bearings sum and 302a, fixed on the base 20, as shown best in Figures 3 and 4. Each of these plungers is provided at its top with a head '304 and on the upper surface of each head are fixed short sections of track 303 corresponding, in size and spacing, to the adjacent ends of the track I98. The plunger 302 is normally in the down positionshown in full lines in Figure 4, wherein the track section 303 is in a plane corresponding to the plane of the followers I01 when in their lowered position, so that, through rotation of the unit, these follower rollers will individually and successively come into a position to overlie the track sections 303 thereof. From this lowered position of the plunger 302, it is adapted to be raised to the dotted line position in Figure 4, wherein the upper surface of the track section 3533 will be flush with the upper surface of the adjacent end of the track I00, so that the follower rollers may readily roll off of the short section 303 onto the track I08. To insure this flush relation, the head 304 preferably has an offset or stop, as at 304a, to engage with the under surface of the track I08 as clearly shown in Figure 4. Through the operation of the lifting elevator shown in Figure 4, as described, the lower drying dies, as they come into the position over said elevator are consecutively lifted from their lower, open position to their upper closed positions.

Figure 3 shows the lowering elevator constructed the same as the lifting elevator of Figure 4, but shown in Figure 3 in full lines in its upper position and in dotted lines in its lower position.

Vertical reciprocation may be imparted to these elevators in synchronized relation to the step by step rotary movement of the drying unit, by the employment of appropriate operating means, one convenient and highly practical form of which is best illustrated :in Figures 1 and 2 of the drawings. Here the lower ends of the two plungers 30I and 302 are shown as connected by links 301 and 308, respectively, to the opposite ends of an offset rocker or lever I306, pivoted intermediate its ends for oscillation on a fixed horizontal pin 306a. Rigid with this offset rocker is an opcratingarm 309, connectedby means of a pitman 3!!) to a cam follower 3 which is operable by a cam 3l2. The end of the pitman which carries the cam is supported by a hanger 313 and the cam track of the cam 3l2 is so shaped as to oscillate the operating arm 309 of the rocker to alternately raise and lower the elevators in such manner that, when the lifting elevator is raised, the lowering elevator is lowered. The cam 3l2 is fixed upon any appropriate constantly operating shaft 6| which may, in practice, be the main drive shaft 6] of the machine shown in my patent or an extension of said shaft. By thus tying in the operation of the rocker arm to the other operating parts of the machine, the movements of this arm are synchronized, so as to raise and lower the elevators in timed relation to the intermittent rotary movement of the drying unit, whereby the lower drying dies may be raised and lowered during periods of rest between the intermittent periods of rotation of said unit.

The arrangement shown in Figure 1 for operating the elevators is highly satisfactory, for the timing is such that the operation of the lifting elevator to raise any particular lower drying dies is coincident with the operation of the lowering elevator to lower another drying die and thus there is a substantially balanced condition of the parts which requires the expenditure of very little power to actuate them.

In practice one group of followers, functioning in the drying cycle, move along the track H38 intermittently in cumulative increments of their travel from its forward end B, in Figure 4 to its rear end L in Figure 3, while other followers are moving in the lowered positions (for discharging dried articles and receiving fresh) from the lowering elevator to the lifting elevator. The timing is such that a follower leaves the track H13 and occupies a position on the lowering elevator, as shown in Figure3, at the same time as another follower rides onto the track section 303 of the lifting elevator in Figure 4. As these two followers come to rest upon cessation of rotation of the drying unit, the cam 3 i2 operates both elevators simultaneously to lower the follower on the lowering elevator and raise the follower on the lifting elevator. The lowering elevator remains in its lowered position, as shown in dotted lines in Figure 3, and the lifting elevator remains in the position shown in dotted lines in Figure 4 until the next period of rotation of the drying unit. The initial movement serves to move the follower which has been lifted, off of the lifting elevator onto the track Iii-8, and the follower which has been lowered, off of the lowering elevator, whereupon the elevators immediately change their position, so that by the time the drying unit moves through its next increment of rotation, both elevators will have been restored to the full line positions of Figures 3 and 4 and be ready to receive succeeding followers. The positions of the followers on the track H38 show the angular movement of the followers for each rotative step of the drying unit.

In the drawings, the plungers 36! and 3B2 are shown as having rigid connection with their heads 303, so that their operations are non-yielding. In practice I may make each of the plungers 3M and 382 of two telescoping sections with a spring between them, so that, as the elevators are raised and the offsets 304a come into contact with the under side of the track I08, slight variations in the height of the track may be compensated for by the yieldable connection between these telescopic sections. This may be at times desirable, due to the fact that the track I03 in the machine is yieldably supported and is capable of adjustment to suit conditions and a corresponding ability of the elevators to yield to compensate for these variations may likewise be desirable, so as to produce a more smooth running machine.

The track I08 has been generally described as substantially horizontal throughout. However, in practice it may be desirable to so adjust the track that the forward end thereof will be somewhat lower than the remainder of the track and the same may be true at times with respect to the rear end of the track. Consequently the track is mounted for vertical adjustment. Moreover, there is always a possibility, when operating upon pulp articles, that the several pulp articles may vary in thickness and in some cases in the operation of a pulp molding machine, some particular article may be skipped in the feed from the forming die to the drying dies and be picked up with a subsequent article so that the two articles are fed to the drying dies in superimposed relation. This results in increased thickness for which the machine should compensate in order to preclude breakage. For these and other reasons the track is yieldably supported so as to automatically compensate for different spacing between the drying dies of each couple. The accompanying drawings show a very satisfactory form of track support for the purposes stated and this support will now be described.

Mounted on the outer side of the base 20 directly below the cam track I08, are a succession of relatively closely spaced apart brackets 3M shown best in Figures 3, 4 and 5. Each of these brackets comprises a plate 5H5 rigidly bolted or welded to the upright Wall of the base 29 and this plate SIE carries an outstanding supporting arm 316 having two upright bosses 3H and 3"! which are spaced apart in a direction away from the base 20. At opposite sides of the supporting arm Sit are a pair of outstanding lugs 3l9. Positioned above the supporting arm 3| 6 is a yoke 329 on which the two runways of the track H38 bear and to which they are secured. The yoke 32!! is tied down to the supporting arm 3H5 by means of bolts 32L the lower ends of which receive nuts below the bosses 3H and Bit. On the under side of the opposite ends of the yoke are two spring bearers 322, which rest on the tops of coil springs 323. Beneath these coil springs are cups 32 and extending upwardly through these cups are threaded posts 325 which are received in sockets in the lugs 319, so 'as to maintain the springs 323 coaxial therewith. Nuts 326 are threaded on to these posts '325 to place the springs 323 under the compression necessary to sustain the pressure which it is desired to' apply to the pulp articles between the drying dies. By adjusting the nuts on the bolts 32f, the maximum elevation of the track may be controlled, while adjustment of the nuts 326 will regulate the springs 32% to control the pressure required to depress the track from its maximum elevation. Thus the track is held in a normal position of adjustment at closely spaced apart distances throughout its length, but it is nevertheless capable of yielding downwardly as and when conditions so require or the adjustment of pressures throughout the drying cycle may dictate.

The structure of this invention will function with marked efficiency when employed in a machine of the character shown in my aforesad patent although not necessarily limited to use in a machine of this particular construction. The invention is therefore to be understood as fully commensurate with the appended claims.

Having thus fully described the invention, what I claim as new and desire to secure by Letters Patent is:

1. In a machine for drying molded pulp articles: a plurality of pairs of superimposed coaxial dies arranged in annular spaced sequence and mounted to rotate about a fixed vertical axis with the upper dies of said pairs arranged at a substantially fixed elevation and the corresponding lower dies vertically movable toward and away from said upper dies, a vertically reciprocating lifting elevator for raising the lower dies in succession into cooperation with their corresponding upper mating dies at one point in the path of rotation of said a vertically reciprocating lowering elevator for lowering said lower dies at another point in the path of rotation thereof, a rocker pivoted to a fixed support intern'iediate its opposite ends with its ends connected to the two elevators, means for tilting the rocker alternately in opposite directions to alternately raise and lower the elevators, and means for holding the lower dies in cooperative relation with the upper dies during the travel of said dies from the lifting elevator to the lowering elevator.

2. In a machine for drying molded pulp articles: a plurality of pairs of superimposed coaxial dies arran ed in annular spaced sequence and mounted to rotate about a fixed vertical axis with the upper dies of said pairs arranged at a substantially fixed elevation and the corresponding lower dies vertically movable toward and away from said upper dies, a vertically reciprocating lifting elevator for raising the lower dies in succession into cooperation with their corresponding upper mating dies at one point in the path of rotation of said dies, a vertically reciprocating lowering elevator for lowering said lower dies at another point in the path of rotation thereof, an operating mechanism for raising one of the elevators while lowering the other and vice versa, an operating mechanism for intermittently rotating the dies with interspersed intervals of dwell of suiiicient duration to permit of operation of the elevators to raise and lower the lower dies during such intervals, and means for holding the lower dies in cooperative relation with the upper dies during the rotary travel of said dies from the lifting elevator to the lowering elevator.

3. In a machine for drying molded pulp articles: a plurality of pairs of superimposed coaxial dies arranged in annular spaced sequence and mounted to rotate about a fixed vertical axis with the upper dies of said pairs arranged at a substantially fixed elevation and the corresponding lower dies vertically movable toward and away from said upper dies, a lifting elevator common to all the lower dies for raising the lower dies in succession into cooperation with their corresponding upper mating dies at one point in the path of rotation of said dies, a lowering elevator common to all the lower dies for lowering said lower dies at another point in the path oi rotation thereof, guides for guiding each of said elevators for vertical movement, operating mechanism for raising one of said elevators while lowering the other and vice versa, an operating mechanism for intermittently rotating the dies with interspersed intervals or" dwell, both of said operating mechanisms being synchronized to operate the elevators during intervals of dwell of the dies, and an arcuate track for holding the lower dies in cooperative relation with the upper dies during the travel of said dies from the lifting elevator to the lowering elevator, whereby all of said lower dies are successively vertically moved into and out of mating relation with their mating upper dies by one lifting elevator and one lowering elevator located at two spaced apart fixed points in the path of rotation of said dies.

4. In a machine for drying molded pulp articles: a plurality of pairs of superimposed coaxial dies arranged in annular spaced sequence and mounted to rotate about a fixed vertical axis with the upper dies of said pairs arranged at a substantially fixed elevation and the corresponding lower dies vertically movable toward and away from said upper dies, a lifting elevator common to all the lower dies for raising the lower dies in succession into cooperation with their corresponding upper mating dies at one point in the path of rotation of said dies, a lowering elevator common to all the lower dies for lowering said lower dies at another point in the path of rotation thereof, guides for guiding each of said elevators for vertical movement, an operating mechanism for raising one of said elevators while lowering the other and vice versa, an operating mechanism for intermittently rotating the dies with interspersed intervals of dwell, both of said operating mechanisms being synchronized to operate the elevators during intervals of dwell of the dies, an arcuate track for holding the lower dies in cooperative relation with the upper dies during the travel of said dies from the lifting elevator to the lowering elevator, whereby all of said lower dies are successively vertically moved into and out of mating relation with their mating upper dies by one lifting elevator and one lowerin elevator located at two spaced apart fixed points in the path of rotation of said dies, springs underlying said arcuate track to support the same, and means for varying the resistance to deflection of said springs to vary the pressure imposed upon articles positioned between said mating dies while in mating relation.

5. In a machine for drying molded pulp articles: a plurality of pairs of superimposed coaxial dies arranged in annular spaced sequence and mounted to rotate about a fixed vertical axis with the upper dies of said pairs arranged at a substantially fixed elevation and the corresponding lower dies vertically movable toward and away from said upper dies, each of said lower dies being mounted on a plunger guided for vertical movement and having a cam follower, an arcuate cam track all parts of which are positioned in a substantially horizontal plane and over which track the followers are adapted to ride to hold the lower dies in mating relation with the upper dies as the dies are rotated, a lifting elevator common to all the lower dies and positioned at one end of said track, a lowering elevator common to all the lower dies and positioned at the other end of said track, guides for guiding each of said elevators for vertical movement from the track elevation to a depressed elevation and vice versa, means for raising one of the elevators while lowering the other and vice versa, and means for intermittently rotating the dies to position the cam followers of the lower dies in succession upon the lifting elevator when the latter is in a lowered position and onto the lowermg elevator when the latter is in raised position, there being intervening intervals-of dwell of sufficient duration between the rotative movements of the dies to permit operation of the elevators to raise one lower die to the elevation of the cam track and to lower another of said lower dies to said depressed elevation.

6. In a machine for drying molded pulp articles: a plurality of pairs of superimposed coaxial dies arranged in angular spaced sequence, means for intermittently rotating all of said pairs of dies about a fixed vertical axis with interspersed intervals of dwell, the upper dies of said pairs being mounted at a substantially fixed elevation and the corresponding lower dies being vertically movable toward and away from their upper mating dies, operating spindles secured to the lower dies and provided with cam followers, an arcuate cam track coaxial with said fixed vertical axis and having a forward end and a rear end and adapted to be traversed by said cam followers to hold the lower dies in raised positions during a part of the rotary movement of said dies, an elevator adapted for up and down reciprocating movement in fixed position at the forward end of the track to engage with successive cam followers and raise the corresponding lower dies to the level of the cam track during successive REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,266,449 Fuccher May 14, 1918 1,377,342 Harbrecht May 10, 1921 2,070,040 Chapman Feb. 9, 1937 2,164,530 Larsen July 4, 1939 2,257,573 Randall Sept. 30, 1941 2,380,942 Chaplin Aug. 7, 1945 2,383,781 Dorrell Aug. 28, 1945 2,388,828 Chaplin Nov. 13, 1945 

